On Friday the prison population in England and Wales broke through the 88,000 barrier for the first time.
When Ken Clarke was last in charge of prisons in the early '90s the, average prison population was just over 44,000. Since that time commentators have argued that the UK is experiencing a new era of crime and punishment where 'law and order' politics dominate and the only punishment acceptable to the public is prison.
We do indeed seem locked in a debate where those who support prison are 'tough' and those who advocate almost any other punishment are dismissed as 'soft on crime'.
Yet a lesser-noticed government impact assessment, published last week, estimated that the combined measures in the Green Paper and the Legal Aid, Sentencing and Punishment of Offenders Bill, would lead to a reduction in demand for prison places of 2,600 by the end of this parliament.
For the first time in recent history, there is concerted action to find alternative, more effective solutions to crime, rather than simply trying to build our way out of the crisis by locking up ever increasing numbers.
These figures were, perhaps optimistically, based on the medium prison projection of the Ministry of Justice published earlier in October.
In this analysis, government had expected a 2% rise in the prison population from June 2011 up until August 2012 because of the riots, and then a 0% growth in the following year as the majority of public disorder prisoners complete their order.
Given how far we have departed from the medium case scenario (already exceeding the estimate by over a 1000 prisoners with many more months of sentencing to go), it looks like a flat-lining custodial population is the most that penal campaigners can expect; the reality could be worse.
With a custodial estate near breaking point and public finances under huge pressure, it is disappointing that the government has chosen to insert new mandatory minimums into the justice bill.
If passed, all 16 and 17-year-olds convicted of threatening people with a knife will get a mandatory minimum custodial sentence of four months (of which they will likely serve two months in prison).
According to the impact assessment this measure will require 30-60 additional prison places, at an annual cost to the taxpayer of between £2 and £4 million.
Whilst every serious-minded person wants to tackle knife crime, there should be a genuine debate about the most effective way of doing this. The government's reason for the mandatory minimums for teenagers was "sending a strong message". Sounds good in theory - the only problem is the last major government-sponsored review of sentencing, the Halliday Report concluded that there is no empirical evidence for the effectiveness of deterrent sentencing.
Sending a message might feel good, but will it be received?
More worrying the Chief Inspector of Prisons recently reported that his prison visits had revealed first-time inmates on riot charges joining gangs for their own protection. Former Home Secretary, Douglas Hurd, got it (partly) right when he said "Prison is an expensive way of making bad people worse."
The influential Centre for Social Justice has put the case strongly over the past few years that the justice system is dealing with the consequences of social breakdown and has argued for the abolition of short sentences of less than two months. Addressing the Centre for Social Justice in 2006 David Cameron said "there is a pretty obvious connection between one's circumstances and one's behaviour."
Quite. The overly-confident assumption that mandatory prison sentences can begin to address teenage offending is naive at best. Prison simply cannot address the complex social problems underlying such behaviour, as is clear from the high reoffending rates for young people released from custody. As the justice bill reaches the Lords this week, perhaps it is time for the Conservative centre ground to re-exert its influence. Penal reform is not 'soft' but recognises the limits of the justice system and looks to the evidence for a sensible way forward.